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Subject: Re: [PATCH] mm: vmscan: correct nr_reclaimed for THP
To:     William Kucharski <william.kucharski@oracle.com>,
        "Huang, Ying" <ying.huang@intel.com>
Cc:     hannes@cmpxchg.org, mhocko@suse.com, mgorman@techsingularity.net,
        kirill.shutemov@linux.intel.com, hughd@google.com,
        akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <1557447392-61607-1-git-send-email-yang.shi@linux.alibaba.com>
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 <1fb73973-f409-1411-423b-c48895d3dde8@linux.alibaba.com>
 <87tve3j9jf.fsf@yhuang-dev.intel.com>
 <640160C2-4579-45FC-AABB-B60185A2348D@oracle.com>
From:   Yang Shi <yang.shi@linux.alibaba.com>
Message-ID: <b8930783-ec73-7330-903f-93a81efb2cd3@linux.alibaba.com>
Date:   Fri, 10 May 2019 08:48:58 -0700
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On 5/9/19 9:33 PM, William Kucharski wrote:
>
>> On May 9, 2019, at 9:03 PM, Huang, Ying <ying.huang@intel.com> wrote:
>>
>> Yang Shi <yang.shi@linux.alibaba.com> writes:
>>
>>> On 5/9/19 7:12 PM, Huang, Ying wrote:
>>>> How about to change this to
>>>>
>>>>
>>>>          nr_reclaimed += hpage_nr_pages(page);
>>> Either is fine to me. Is this faster than "1 << compound_order(page)"?
>> I think the readability is a little better.  And this will become
>>
>>         nr_reclaimed += 1
>>
>> if CONFIG_TRANSPARENT_HUAGEPAGE is disabled.
> I find this more legible and self documenting, and it avoids the bit shift
> operation completely on the majority of systems where THP is not configured.

Yes, I do agree. Thanks for the suggestion.
>